Ultrasonography has major role in assisting the obstetrician to evaluate the pregnant uterus. Aim of this work to measure the capabilities of US in evaluating the integrity of C.S scar. Results: the LUS thickness by both TAU and TVU in is thinner significantly in C.S cases compared to the control group. It was found that LUS thickness is thinner C.S cases é alleged uterine action. Intraoperatively, Patient é very thin LUS during labour thickness (lowers than 2 mm), reveled paper thin LUS. cases of C.S é placnta previa (9 cases), Ultrasound reveals intraplacental lacunae which may be diffuse (3cases) or focal (6 cases), Doppler study of these lacunae reveled absent or low flow (7cases) or high velocity é pulsatile flow (2cases).